border-1px($color)
  position: relative
  &:after
    display: block
    position: absolute
    left: 0
    bottom: 0
    width: 100%
    border-top: 1px solid $color
    content: ''

border-none()
  &:after
    border-top: none

bg-img($url) {
  background-image: url($url + "@2x.png")
  @media (-webkit-min-device-pixel-ratio: 3),(min-device-pixel-ratio: 3) {
    background-image: url($url + "@3x.png");
  }
}

base-img-url = './img/'

